Group dispatch calling between users is becoming increasingly popular. One of the main reasons for its popularity is that the setup time for a group dispatch call is relatively small as compared to, for example, the setup time for a group cellular telephone call (i.e., a conference call). Another distinction between a dispatch communication and a cellular telephone communication is that a dispatch communication is typically half-duplex. That is, a dispatch communication link is allocated to a single user at a time for transmitting voice and/or data.
In the past, group dispatch calling (a dispatch call between a calling party and two or more target parties) was limited to users situated within a limited geographical area, such as, for example, Chicago. The reason is that the dispatch communications network processing group dispatch calls had limited coverage within such geographical area. Thus, if a user roamed beyond the geographical area covered by the corresponding dispatch communications network, for example, to Los Angeles, the user would not be able to make group dispatch calls.
Accordingly, there is a need for a system and method of providing group dispatch calling between users in distinct geographical areas covered respectively by distinct intra-area dispatch communications networks.